2022 Intensely Managed Soybean Trial Results

Johnston County growers plant between 45,000 and 55,000 acres of soybeans each year with an average yield of 35 bushels/A. Many soybean acres are planted on medium to low-yielding soil types. Growers have to budget input costs to determine how much they can spend on production costs and still make a profit.

Working with a local grower, we initiated a four replication, randomized complete block field trial to determine if scouting, tissue sampling, and timely insecticide and fungicide applications would increase profits above the breakeven point. The trial was placed on a Marlbaro sandy loam soil type with a realistic yield estimate of 44 bushels/A. Preplant fertilizer was applied according to the results of an NCDA&CS soil sample report. Tissue samples were taken at V-3 and R-1. Weekly scouting was initiated on July 28th and continued through September 15th. Two applications of foliar fertilizer and Bifenthrin were made to plots as needed, and one application of Revytek and Intrepid Edge was made at R-2-R3, There was an untreated control (UTC), and a cadillac treatment that received an application every time anything was done to the other treatments. The following slides are a summary of the results.

•When applied as needed on Time!

•Revytek - 5.3 bushel/A increase

•2 applications of Bifenthrin - 4.9 bushel/A increase due to stinkbug control compared to a 1.7 bushel/A increase with one application on 7/29.

•Intrepid Edge - 5.3 bushel/A increase due to lower pod damage

•Foliar feed - 1.5 bushel/A increase compared to check

–Based on tissue results, an across-the-board foliar feed was unnecessary as nutrient levels exceeded NCDA&CS recommended levels.

•All Treatments - 6.8 bushel/A increase

–Most likely due to pod protection and retention from the fungicide and insecticide treatments.

•Although yield differences were not as significant as they were last year, intensely managing the soybean crop made money in 2022

•Mid and end-of-season dry weather had an adverse effect on yields.

•Trial needs to be repeated more times in different years

A multitude of strategies are needed to effectively manage foliar diseases which can limit NC soybean yield annually that include selecting resistance varieties, cultural management practices, and using foliar fungicides.

Data from these on-farm trials and complementing small-plot research confirms that foliar fungicides can provide considerable yield protection in North Carolina soybean production, which means that foliar diseases are often hurting yield.

Generally newer fungicidal chemistries (multiple MOA) provide superior disease protection.

The impact of foliar fungicide product and timing on yield varies across environments and underscores the need for precision disease management

NC State University and N.C. A&T State University works in tandem with federal, state, and local governments to form a strategic partnership called N.C. Cooperative Extension.

Disclaimer:
Recommendations for the use of agricultural chemicals and variety information are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by North Carolina Cooperative Extension nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your county Cooperative Extension agent.